The amount of organic matter in sediments also depends on th

2019-05-16 09:42 admin
Man is used for photosynthesis. The thickness of this zone varies from 2 oom in the open ocean to 5 OM in the coastal waters, while the quality, convection, oxygen distribution, glacier and seabed topography may affect the generation and distribution of organic matter.
There are only a few meters in the lagoon. It is estimated that 6ox to'7o% of organic matter in geological bodies is provided by plankton and bacteria. In addition, Table 8-10 of W is the original yield of bio-organic carbon in different aquatic environments, from which we can see that the original yield of organic carbon in freshwater environment only accounts for more than 1% of total organic matter. Phytoplankton in the ocean provides about 95% of the original organic matter (with a total weight of 4oGt per year).
The primary productivity of the remaining 3 traces is mainly from coastal ecosystems, such as salt marshes and mangrove marshes in tidal zones. Coral reefs, although particularly developed in some areas, contribute less than 1% of the primary organic matter to the whole ecosystem.
Table 8-10 Estimation of biomass and primary yield in aquatic environment
Open ocean 332.0.46 32.1 (gc/m2a)
Upwelling W 0.40.004 0.2 100
Continental Shelf 26.60.13 7.3 500
Algae mat and reef 0.60.54 0.52?
Harbour (open water) 1.40.63 0.1 830
Marsh 2.0 10.4 1.3 70
Lakes and rivers 2.0 0.02 0.6 650
According to Kiliops and Kiliops, 1993.300
And it really enters into the sedimentary circle and becomes an organic deposit for accumulation and preservation.
Earth Erren takes human space, and only 0.01% of the dead organism organic matter is preserved at the general marine sedimentation rate. However, some marine environments, such as the slope of continental margin, are good places for the preservation of organic matter. In addition, the pre-delta sediments and continental lakes and marshes in the transitional environment between sea and land are also good environments for organic matter accumulation.
The amount of organic matter in sediments also depends on the sedimentary environment. In the high-energy zone of the coastal area, although there is abundant biological productivity, organic matter is less preserved due to the intensification of the biological and chemical degradation of organic matter due to strong currents and high oxygen content in water. Coarse-grained sand rarely contains more than 0.5 terbium organic carbon, and the preservation of organic matter generally increases from high-energy to low-energy sediments (from sand to clay). This can also be proved by the content of organic matter in rocks. Sandstone is deposited in high-energy oxidation environment with low content of secondary organic matter. Shale and clay are deposits with high organic matter content under the condition of reduction of plutonium energy. The organic matter content of carbonate is generally medium.

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